This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Prevascularized tissue constructs were built by coculture of fibroblasts and endothelial cells in a fibrin gel. The endothelial cells formed interconnected vessel networks. In order to visualize the vessel networks, the endothelial cells were fluorescently labled and imaged.